ROME -- World No. 1 Caroline Wozniacki and former top-ranked star Maria Sharapova secured berths in Saturday's semifinals, while French Open champion Francesca Schiavone of Italy came up a quarterfinal loser Friday at the $2.05 million Internazionali d'Italia tennis event.
Wozniacki needed all three sets to stave off fifth-seeded former No. 1 Jelena Jankovic 6-3, 1-6, 6-3 on the red clay at Foro Italico. Wozniacki prevailed in 2 hours, 23 minutes in a match that featured 13 service breaks, including seven by the Danish winner.
The Serbian Jankovic was the back-to-back Rome champion in 2007 and 2008 and last year's runner-up here to Spain's Maria Jose Martinez Sanchez.
Wozniacki and Sharapova will square off in Saturday's marquee semifinal at Foro Italico. The two stars have split four career matchups, but Sharapova is 1-0 on clay, with the victory coming in the third round here in Rome in 2008. The Dane, however, has won their last two meetings overall.
A seventh-seeded Sharapova was trailing third-seeded Victoria Azarenka 4-6, 3-0 when the Belarusian slugger retired from their highly-anticipated bout with an apparent right arm injury.
Azarenka summoned a trainer after losing the first game of the second set. She grimaced and bent over in pain in the next two games, and then called it a day.
This marks the third time that Azarenka has retired from a match this season. She's retired from bouts in three of her last six tournaments.
The 21-year-old Azarenka was last week's Madrid runner-up to rising Czech lefthander Petra Kvitova and had won 18 of her previous 20 matches, including titles in Miami and Marbella, before retiring Friday in Rome.
Meanwhile, a second-seeded Schiavone succumbed to Aussie Samantha Stosur in a rematch of last year's Roland Garros finale. A sixth-seeded Stosur avenged last year's French Open setback with a 6-2, 6-4 victory at Foro Italico. Stosur posted the upset in 1 hour, 17 minutes by holding her serve throughout while breaking the Milan native Schiavone on three occasions.
Australian Open runner-up Li Na, seeded fourth this week, landed in the semis by leveling Hungarian Greta Arn 6-3, 6-1. The Chinese slugger Li and Stosur will do battle here on Saturday.
The 2011 Rome titlist will collect $360,000.